Residual stress profiling in the ferrite and cementite phases of cold-drawn steel rods by synchrotron X-ray and neutron diffraction

The concept of the yield locus as a means of representing the plastic anisotropy of a textured material is remembered. It is shown how such yield loci can be used in a very general way, i.e. in full six-dimensional stress space. As an example of how such yield loci can actually be obtained, the series expansion method based on Taylor factors is explained. It is finally shown that these six-dimensional yield loci can be approximated by analytical expressions and under such form brought into finite element calculations of elasto-plastic forming processes.

Application of yield loci calculated from texture data

Role of drawing-induced residual stresses and strains in the hydrogen embrittlement susceptibility of prestressing steels

The mechanical response of two-phase materials during plastic co-deformation is examined with a particular emphasis on the role of the internal stresses developed during deformation. A framework is developed to describe the accumulation of these internal stresses during plastic co-deformation in terms of a small number of physical parameters. This simplified framework is used to rationalize the observed behaviour of copper–chromium and copper–niobium two-phase materials in terms of their monotonic strain hardening rates, the response to changes in path (tension/compression) and their dimensional stability on heating.

Role of internal stresses in co-deformed two-phase materials

Microstructure and mechanical properties of cold-drawn pearlitic wires affect by inherited texture

This paper presents a study on residual stress in cold drawn wire of low carbon steel by means of finite-element method (FEM) simulation and X-ray diffraction. A thick wire with a diameter of 17.9 mm drawn from an annealed wire with a diameter of 20.1 mm was investigated. First, FEM simulations were performed based on a suitable model describing the boundary conditions and the exact material behavior. Due to the initial texture in the original material, the anisotropy of the material plastic behavior was taken into account on the basis of the texture measurement of the wire. Instead of the isotropic von Mises yield criterion, a texture-based anisotropic yield locus was incorporated into the model to simulate the wire drawing process and calculate residual stresses. Next, X-ray diffraction measurements were carried out at the surface of the wire to obtain the distribution of the lattice spacing versus sin 2 ψ , from which the macroscopic residual stresses at the wire surface were calculated. The comparison between the results from the simulations and the measurements shows that a good agreement has been reached.

Residual stress determination in cold drawn steel wire by FEM simulation and X-ray diffraction

This paper presents a study on the strain rate effect during high-speed wire drawing process by means of finite element simulation. Based on the quasistatic stresses obtained by normal tensile tests and dynamic stresses at high strain rates by split Hopkinson pressure bar tests, the wire drawing process was simulated for low carbon steel and high carbon steel. The results show that both the deformation process and the final properties of drawn wires are influenced by the strain rate.

http://iopscience.iop.org/article/10.1088/0965-0393/10/3/302/pdf

Strain rate effect in high-speed wire drawing process

This paper presents a study of residual stress in cold drawn wires of low carbon steel by means of FEM simulation and X-ray diffraction. First, FEM simulations were performed to simulate the wire drawing process and calculate residual stresses. Due to the initial texture in the original material, a texture based anisotropic yield locus was incorporated into the model to take the plastic anisotropy into account. Next, X-ray diffraction measurements were carried out at the surface of the wire to obtain the distribution of the lattice spacing versus sin 2 ψ, from which the macroscopic residual stresses at the wire surface were calculated. The comparison between the results from the simulations and the measurements shows that a good agreement has been reached.

F Mei

Papers

Residual stress determination in cold drawn steel wire by FEM simulation and X-ray diffraction

Strain rate effect in high-speed wire drawing process

Residual Stress Determination in Cold Drawn Steel Wire by FEM Simulation and X-Ray Diffraction

The study of residual stresses in cold drawn steel wire by means of X-ray diffraction and finite element simulation